Composition for recoating acoustic tile and the like



a 2,985,605 IQQ Patented May 23, 1961 COMPOSITIQN. FOR RECOA'IING ACOUSTIC TILE AND THE LIKE Jerzy Do1'nanski, Hudson, and James G. Linn, Parma Heights, Ohio, assignors to The Sherwin-Williams Company, Cleveland, Ohio, a corporation of Ohio No Drawing. Filed Oct. s, 1958, Ser'. No. 765,949

2 Claims. (Cl. 260 -23) This invention relates, as indicated, to compositions suitable for use in the recoating of acoustic tiles and the like which have become soiled and stained in the process of aging. It is a principal purpose of these compositions to enable the restoration of surfaces covered with such acoustic tile or material to their original appearance without in any way impairing the utility of such tile or board for the purpose for which it was installed;

The restoration of the original appearance of ceilings,

for-example, covered with acoustic fiberglass boards has been heretofore virtually impossible because simple washing causes smudging of the deposited dirt, and re-' painting, using conventional paints, causes clogging'of the holes in the tiles resultingin substantial or complete elimination of the noise-absorbing properties of'the tiles. The coating compositions of the-present invention are designed to obviate these disadvantages.

appended claims, the following description setting. forth inrdctailcertainillustative embodiments of the invention, suchdisclosedmeans constituting, however, but a few of.thevar ioi1s forms in which the principle of this'invention may becmployed. 7 y y v Broadly stated, therefore, this inventionis in theprovisionof a recoatingcompositionjfor acoustic tiles andboards based on polyacrylic resin solution, in ablend of: aromaticpaliphatic and .polar solve'nts, pi g'rnentedwith a. white pigment" and a high oil absorption extender,

and containinga polyvalent mantra fattyacidin addition to a very minor amount of water.

A more completeiunderstanding 'of'r'the invention may be, had by reference to the following,illustrativeexample of thecomposition of the coafing. It should beundrstood, however, that the detailed description, while indicating preferred composition of the invention, is given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art.

The coatings hereof arecapable of restoring original appearanceof These compositions- 2 Example I Parts by weight Poly n-butyl methacrylate resin 14.60 Mineral spirits 39;87' Solvent naphtha 693' Calcium stearate 0.30 Titanium dioxide 28170 Calcium silicate 1.75 Monobutyl ether of ethylene glycol 7.83. Water 0.02

Total 100.00"

The coating is prepared in the following manner. The resin is dissolved in about half of the mineral spirits and about half of the solvent naphtha under high speed: agitation. The titanium dioxide, calcium silicate and; calcium stearate are dispersed in about one-half of the resulting resin solution. Enough mineral spirits isthen added to the blend to obtain a. satisfactory consistency. off the paste for the selected grinding equipment. The solid phase should be dispersed enough on the grinding equip ment to} give a Hegman gage reading of 2. The balance of the resin solution and the balance of the solvent according to the formula is then added. 7

When thus prepared, the coating has the right con sistency for both brush and roller application.

Although in the preceding example poly n-butyl meth acrylate resin has been used, any polyalkyl methacrylate resin or any polyalkyl ethacrylate resin may be'usedi For example, we may use polymethyl methacrylate, polyethyl methacrylate, polypropyl methacrylate, polyisopropyl methacrylate, polybutyl methacrylate, polyamyl methacrylate, polymethyl ethacrylate, polyethyl acrylate,; polybutyl' acrylate, polybutyl etha'crylate, etc. For the, purposes of this specification, the amount of such resinr as. solids will'be regarded as 100 parts by-weight. in the formulations in order to fix the proportion ranges. of the. remaining ingredients.

The mineral spirits or painters naphtha portion of this. compositionis in eflect a diluent. Any of a numberof narrow-boiling-range fractions of petroleum of largely aliphatic character having boiling points within the range. of about ZOO-300 F. may be used for this purpose. Quite clearly pure or commercial hydrocarbon mixtures such as commercial hexane composed of normal hexane. isohexane, and all of the remaining'hexane isomer in various proportionsmay be used. Normal hexane, as such, normal cyclohexane, heptane, octane, and mixtures of such normally liquid aliphatic hydrocarbon mate rials Whether of straight chain, cyclic, or saturated straight chain or saturated cyclic, or unsaturated straight chain suchasoctene'or hexene,,or commercial mixtures: ofthese. materials, or cyclohexene, mayalso be usedzin: place ofthemineral spirits- Thisportion of theformu. lationis present. iii-"the proportion of fromv about 20.0, to about 300 parts by weight per 100 parts of the'resin: above described. y

The; next.' important portion of. the: compositions; 'ofifthis, invention contemplates an aromatic hydrocarbon solvent. This may be benzene, xylene, toluene, mixtures of these, or commercial petroleum fractions of high aromatic content. Frequently this type of solvent is referred to in the trade as solvent naphtha. Boiling point is generally in the range of from about C. to about 180 C.

The solvent, as distinguished from the diluent, is usually present in amounts ranging from about 30 to 60 parts by weight per 100 parts of the acrylate resin.

The next important ingredient of the compositions of this invention is an alkaline earth metal soap of a higher molecular weight fatty acid, that is, one containing from to carbon atoms. Any of the alkaline earth metals may be used for this purpose and specific examples of such alkaline earth metal soaps of higher molecular weight fatty acids include calcium decate, barium decate, magnesium decate, strontium decate, calcium undecate, barium undecate, calcium ricinoleate, barium ricinoleate, calcium laurate, barium laurate, magnesium laurate, calcium oleate, barium oleate, magnesium oleate, strontium oleate, calcium stearate, barium stearate, calcium alpha hydroxy stearate, calcium 12 hydroxy stearate, calcium 9 hydroxy stearate, calcium 10 hydroxy stearate, calcium palmitate, barium palmitate, calcium soap of linseed oil fatty acids, the calcium soap of soya-bean oil fatty acid, calcium rosinate, calcium naphthenate, barium rosinate, barium naphthenate, magnesium naphthenate, etc. Any of the foregoing alkaline earth metal soaps of higher molecular weight fatty acids may be used in replacement of the alkaline earth metal soap specified above in Example I in an amount ranging from about .5 to 5 parts by weight per 100 parts of the acrylate resin.

The next principal ingredient as illustrated by the specific example above is a hiding pigment such as titanium dioxide whether rutile or anatase, and this material may be replaced with calcium carbonate, zinc oxide, leaded zinc oxide or mixtures of any of these. The white pigment portion of the compositions of this invention is usually present in amounts ranging from about 150 to 250 parts by weight per 100 parts of the acrylate resin.

, The next important component of the compositions of these inventions is a pigment which is characterized by high oil absorption. Many of these are well known to those skilled in the art and include calcium silicate, magnesium silicate, talc, various finely divided clays, sodium silicate polymers having a very high ratio of silica to alkali, i.e., in the neighborhood of from about 9:1 to about 500:1. The high oil absorption pigment is usually present in these compositions in amounts ranging from about 5 to about 20 parts by weight per 100 parts of resin. i

.The next ingredient of the compositions in accordance with Example I above is a solvent which may be a monoalkyl ether of an alkylene glycol. Specific examples of such materials which are well known to those skilled in the art. as Cellosolves include monoethyl ether of ethylene glycol, monobutyl ether of ethylene glycol, monoethyl ether of propylene glycol, monobutyl ether of propylene glycol, and any of the reasonably available equivalents thereof. This solvent is usually present in the compositions of this invention in amounts ranging from about 30 to about parts by weight per parts of resin.

The next important ingredient of the compositions of this invention is water. Water appears to confer an unusual ease of brushing upon the composition. The water isusually added to the formulation in the form of a very dilute solution in the Cellosolve type ingredient as above mentioned. 7

In summary of the foregoing variations which may be made in the formulation set forth in Example I above,

4 the coating compositions contemplated by the present invention have the following general composition:

Parts by weight Polyalkyl acrylate resin 100 Aliphatic hydrocarbon diluent 200-300 Aromatic hydrocarbon solvent 30-60 Alkaline earth metal soap of a higher molecular weight fatty acid .5-5

White hiding pigment -250 Silicate pigment 5-20 Monoalkyl ether of alkylene. glycol 30-70 Water .03-1

There has thus been provided a white coating composition based on a polyacrylic resin solution in a blend of aromatic, aliphatic, and polar solvents, pigmented with a white pigment and a high oil absorption extender, and containing a polyvalent metal salt of a fatty acid. A unique property of the compositions of this invention is their capability of pulling away from the pores of the tiles shortly after application. Moreover, the coating compositions are balanced in such a way that no effort is required to apply the material by brush or roller because of the thixotropic character of the dispersion. These coatings are also designed such that only one coat applied by brush is required to obliterate the dirt on appreciably aged tiles. No appreciable diminution of the effectiveness of tiles coated with the compositions of this invention as sound-absorbing media has been detected.

Other modes of applying the principle of this invention may be employed instead of those specifically set forth above, changes being made as regards the details herein disclosed, provided the elements set forth in any of the following claims, or the equivalent of such be employed.

It is, therefore, particularly pointed out and distinctly claimed as the invention:

LArecoating composition for acoustic tiles and boards consisting essentially of:

Parts by weight Polyalkyl acrylate resin 100 Aliphatic hydrocarbon diluent 200-300 Aromatic hydrocarbon solvent 30-60 Alkaline earth metal soap of a higher molecular weight fatty acid .5-5

White hiding pigment 150-250 Silicate pigment 5-20 Monoalkyl ether of alkylene glycol 30-70 Water .03-1

said aromatic hydrocarbon solvent being selected from the group consisting of benzene, xylene, toluene, and solvent naphtha. V

2.'A recoating composition for acoustic tiles and boards consisting essentially of:

Parts by weight Poly n-butyl methacrylate 100 Mineral spirits V V 273 Solvent naphtha 48 Calcium stearate 2 Titanium dioxide 197 Calcium silicate v l2 Monobutyl ether of ethylene. glycol 57 Water 0.14

References Cited in the file of this patent UNITED STATES PATENTS 2,413,259 Soday Dec. 24, 1946 

1. A RECOATING COMPOSITION FOR ACOUSTIC TILES AND BOARDS CONSISTING ESSENTIALLY OF: PARTS BY WEIGHT POLYALKYL ACRYLATE RESIN ------------------- 100 AROMATIC HYDROCARBON SOLVENT --------------- 200-300 AROMATIC HYDROCARBON SOLVENT --------------- 30-60 ALKALINE EARTH METAL SOAP OF A HIGHER MOLECULAR WEIGHT FATTY ACID --------------------- .5-5 WHITE HIDING PIGMENT ----------------------- 150-250 SILICATE PIGMENT --------------------------- 5-20 MONOALKYL ETHER OF ALKYLENE GLYCOL --------- 30-70 WATER -------------------------------------- .30-1 SAID AROMATIC HYDROCARBON SOLVENT BEING SELECTED FROM THE GROUP CONSISTING OF BENZENE, XYLENE, TOLUENE, AND SOLVENT NAPHTHA. 